SpaceX is throwing in the towel on fairing recovery, at least in terms of catching them.
There is always a tradeoff between reusability and expendability in terms of minimizing cost per flight. Shuttle had some notoriously bad design decisions, because they anticipated a higher flight rate than they ever got. At the end of the program, it was clear that it would have been cheaper to expend the SRBs than to recover and refurbish them, because of the high fixed costs of the recovery fleet that had to be amortized over a low flight rate. Expending the ET cost tens of millions per flight.
Elon was determined early on to recover as much of the vehicle as possible (they spent years trying to figure out how to recover the upper stage of the Falcon), but he finally decided that the only solution was to scale the vehicle up, and go to stainless steel to handle entry heating, so the focus is on Starship now, and Falcon 9 has reached the end of its development cycle.